a—3a.

3

Of the fourteen fatal accidents, causing sixteen deaths, ten occurred in the West Coast Inspection District. From the foregoing summary it will be seen that ten lives were lost by falls mine, which are becoming more prevalent as the stage of pillar-extraction is being advanced by the bord-and-pillar system. During the first operation of driving bords on seams ranging in thickness up to 30 ft. or more, no special danger was experienced from falls, the coal being worked in two or more layers ; but now that the pillar-extraction stage has been reached at several of the mines, the great height to be supported on timber has proved in many cases a difficult and dangerous proposition, especially where the seam is highly inclined. In such cases " bumps," or diagonal movements of the roof rocks, take place near the edges of the " gob," and the timber, however carefully erected, often proves ineffective, as the superincumbent weight does not fall directly upon the same, but strikes it obliquely, throwing down the props even when standing in great numbers. The difficulty could no doubt be overcome by leaving behind " ribs " and " stumps " of coal of adequate dimensions to support the weight, but these measures, remedial doubtless in the above cases, would possibly create further dangers from gas-accumulations and spontaneous fire of the crushed coal; likewise the loss of marketable coal, together with the increased cost of production owing to more solid work (which is paid for at a higher rate than pillar-work), might have a very injurious effect on the coal-mining industry, and possibly lead to cessation of operations in some cases. The position is a somewhat difficult one, for in no other country, as far as I am aware, does such valuable fuel occur in seams of such considerable thickness. At the Dutch Government's State Collieries at Sumatra a seam of 50 ft. in thickness is almost completely extracted in layers commencing at the floor. As each layer is removed sand is sluiced into the space formerly occupied by the coal-seam ; the layer of coal above is then attacked and in turn filled in by the hydraulic sand filling; and so on until all coal is removed and replaced by sand; but the local conditions in Sumatra are favourable to this method, and it is to be regretted that the undulating form of the New Zealand coal-seams and the absence of beds of sand in proximity to the same render this system inapplicable to this country. The discovery of a safe and economical method by which a high percentage of the thirk coal-seams of New Zealand may be extracted is a subject that deserves special research, but I am uot sanguine of an entirely satisfactory solution. The following statement shows the tons of mineral raised (coal and shale), persons employed, lives lost, &c, from 1878 to 1910 :—

Year. Output of Mineral. Persons employed. Tons of Mineral raised per each Person employpd Underground. Tons of Persons Mineral [ employed raised per | per each Life lost. Life lost. Lives lost per Thousand Persons employed. Number of Deaths. Above. Below. Total. Prior 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 ... 709,931 162,218 231,218 299,923 337,262 378,272 421,764 480,831 511,063 534,353 558,620 613,895 586,445 637,397 668,794 673,315 691,548 719,546 726,654 792,851 840,713 907,033 975,234 1,093,990 1,239,686 1,365,040 1,420,229 1,537,838 1,585,756 1,729,536 1,831,009 1,860,975 1,911,247 2,197,362 147 361 393 338 392 388 414 466 512 416 485 590 506 525 590' 531 556554 617 688 803 717 763 833 1,174 1,143 992 1,159 1,136 366 888 890 1,145 1,213 1,111 1,275 1,251 1,334 1,277 1,196 1,298 1,393 1,274 1,347 1,381 1,447 1,599 1,843 2,066 J 2,082 ! 2,135 ■ 2,525 2,436 2,518 2,767 2,902 3,032 3,463 513 802 1,038 963 1,043 1,249 1,283 1,483 1,605 1,499 1,689 1,717 1,846 1,693 1,681 1,888 1,899 1,799 1,937 1,912 2,003 2,153 2,460 2,754 2,885 2,852 3,288 3,269 3,692 3,910 3,894 4,191 4,599 443 475 540 456 440 503 481 •261 477 523 563 533 516 618 588 609 627 609 593 600 655 665 609 651 687 662 641 633 634 4,771 115,609 149,961 337,262 189,136 210,882 160,277 170,354 139,655 153,474 146,611 79,674 167 ,198 673,315 138,305 119,924 145,331 12,013 210,178 907,033 325,078 273,497 413,228 682,520 355,057 384,459 264,293 288,256 152,584 372,195 273,035 137,335 15 401 519 963 521 624 421 494 375 422 313 231 423 1,681 377 316 360 29 478 2,003 717 615 918 1,443 713 822 546 615 326 778 599 283 66-27 2-49 1-92 104 1-91 1-60 234 201 2-66 2-36 2-37 4-33 2-36 066 2 64 3-16 3-33 3407 209 0-49 1-39 1-62 109 069 1-40 1-21 1-83 1-62 3-07 1-28 1-79 355 341 2 2 1 2 2 3 3 0 4 4 4 8 4 1 5 6 5 66J 4 1 3 4 3 2 4 4 6 6 12 5 7 16 Totals... 31,281,548 233 * No life loBt. t Year of Kaitani ;ata explosion. Year of Brunner explosion.